Air Quality Sensor

This document is currently in the preliminary stage, and therefore, device specifications are subject to change without notice.

This device measures VOC, NOx, CO2, PM (Particulate Matter), relative humidity, and temperature. It transmits data using Modbus RTU communication protocol over the RS-485 standard.

Front View

Bottom View

Technical Specifications

The following table outlines the capabilities of the device.

Property	Value
Onboard sensors	Sensirion SEN55 Environmental Sensor Sensirion SCD41 CO2 Sensor Optional accelerometer for 2-axis angle detection
Memory	Historical data for internal statistics Configuration and calibration storage
Microcontroller	STM32 C0 Series MCU, 32-bit ARM Cortex-M0+

Sensing Specifications

The following table shows sensor characteristics.

Measurement	Accuracy	Min	Max
VOC Index	<±15 VOC Index points or % VOC Index m.v. (the larger)	1	500
NOx Index	<±15 NOx Index points or % NOx Index m.v. (the larger)	1	500
Relative Humidity	@ 25 °C, 30-70 %RH: ±4.5% rH (typical), ±6% rH (maximum)
Temperature	@ 15-30 °C, 50 %RH: ±0.45°C (typical), ±0.7°C (maximum)
PM 1.0	0 to 100 μg/m3: ±[5 μg/m3 + 5 % m.v.] 100 to 1000 μg/m3: ±10 % m.v.	N/A	N/A
PM 2.5	0 to 100 μg/m3: ±[5 μg/m3 + 5 % m.v.] 100 to 1000 μg/m3: ±10 % m.v.	N/A	N/A
PM 4.0	0 to 100 μg/m3: ±25 μg/m3 100 to 1000 μg/m3: ±25 % m.v.	N/A	N/A
PM 10	0 to 100 μg/m3: ±25 μg/m3 100 to 1000 μg/m3: ±25 % m.v.	N/A	N/A
CO2	400 ppm ... 1000 ppm ±(50 ppm + 2.5% of reading) 1001 ppm ... 2000 ppm ±(50 ppm + 3% of reading) 2001 ppm ... 5000 ppm ±(40 ppm + 5% of reading)	400 ppm	5000 ppm

Physical Properties

This table shows the mechanical properties of the device.

Property	Value
Mounting Style	Screw Mount
Dimensions	80w x 60h x 35d mm
Base Material	ASA (Acrylonitrile Styrene Acrylate) Impact, wear, and UV resistant
Weight	< 200g

Environmental Conditions

Environmental Conditions refer to the physical and atmospheric conditions surrounding the device.

Property	Value
Operating Ambient Temperature	10°C…+40°C
Relative Humidity	20%...80% RH
Storage	-20°C…+60°C 10%…90% RH (non-condensing)

Electrical Characteristics

This table indicates the electrical specifications of the device.

Property	Value
Main Supply	DC 5…24V
RS-485	-7…+12V (No internal termination)
Internal Fuse	DC 60V 6A 1206 Case Slow-burning

Absolute Maximum Ratings

Absolute maximum ratings indicate the maximum electrical or environmental parameters this device can withstand without damage.

Stresses above the absolute maximum ratings listed in the table may cause permanent damage to the device. These are stress ratings only, and the functional operation of the device under these conditions is not implied. Exposure to maximum rating conditions for extended periods may affect device reliability.

Property	Value
Operating Ambient Temperature	-10°C…+50°C
Relative Humidity	0%...90% RH (non-condensing)
Main Supply	DC 30V
RS-485	-7…+12V

Connectivity Options

This table lists the communication options of the device.

Property	Value
RS-485	4-Pin connectivity (Power, GND, RS-485 A, RS-485 B)

Communication Protocols

This device supports the following communication protocols.

Modbus Protocol